Wind Turbines Longevity Study

Introduction to the study

All the following information was gathered from the American Wind Energy Association, and is available at their website. What is a reasonable life expectancy for a turbine? ...or, for that matter, any generator system? These are the best number we have to this day.

Data collection

The data that AWEA collected was from schools, builders, other installers, and various publications. Many of the older reports were from older wind turbine related publications to give a back drop on how wind turbines have improved and where they rate vs. newer options. Though these are not truly random samples, I believe they are large enough to be considered representative of the turbine population.

Longevity then and now

The oldest turbine reported and confirmed still active in 2009 was erected in 1968. Analysis of % active over that period suggests a median lifespan of close to 21 years for the industry.

Cause of Failure

Cause of failure was indicated for 355 of the turbines surveyed. The most frequest cause cites for the pre-1980's turbines was "old age" at 42.7% meaning over 20 years of installed operation before the system failed. Alternator and inverter failure was the most common cause "electrical system" in the current group at 37.1%, with old age being cited 9.1% of the time. The table shows the incidence of the most common causes of failure, but remember only failed systems were studeid to find the causes and problems of modern designs and where older systems may have had advantages.

How that Relates to our Turbines

The chart shows the trend as technology has advanced, failures have not gone away so much as the nature of them has changed. Adverse weather, such as lightening strikes, tornadoes and so on has increased not because of fault in the builders, but the fact that other mechanical failures have decreased as building methods have improved. TradeWinds turbines utilize PVC, ABS, and solid core fiberglass in addition to steel in their construction, making them far less likely to attract lightening strikes. Electrical system failure such as inverters and generators has declined not so much because they have made big advances, but more companies such as ours have switched to using Induction Generators which do not require complex inverters or batteries. Grounding failure, this upwards trend shows how dangerous a home built or under built turbine can be, not all turbines are rated for use in our area due to the wind category we are in but this does not stop companies from trying to sell them here. Computer failure has grown drastically, as more companies use high dollar computer controls to regulate their turbines. TradeWinds’ turbines still use the old reliable and far cheaper fault relays in our control enclosure, meaning when something is not right a sensor tells the relay and it trips to lock down the turbine before more damage can occur. Old age, sadly as the turbines have gotten more complex this percent has gone down drastically, at TradeWinds we believe by building a rugged, simple, machine we can help reverse this trend and drastically increase the life span of our units beyond 30 years.

Any turbine you buy today should last 20 years, but the payout time is the most important factor and one must include maintenance in this figure. With TradeWinds‘ turbines our customers can realize a 5 year payback while many companies installed turbines are over twice the price for the same end output.